Fans of the great French director of Les Diaboliques and The Wages of Fear will find much of interest in this documentary about the film that never was. Inferno was elaborately storyboarded with endless tests for experimental camerawork using op art and distorted visuals to denote his lead character's obsessive jealousy. With free experimentation and an "unlimited" budget, the 1964 production sounds like a dream come true, but Clouzot was an insomniac described by fellow workers as "anxious and nervous". He also had a history of being hard on actors, and it all ended tragically, but the footage here suggests this might have been a film to rank with his best.